The present disclosure relates to a module carrier assembly for a motor vehicle for positioning between the A-pillars of the vehicle body, having a transverse carrier extending between the A-pillars and configured as a hollow body profile, and having at least one steering column holder connected to the transverse carrier and supported at the outer side of the transverse carrier in the x-direction. As used herein, the x-direction corresponds to a vehicle's longitudinal axis; the y-direction is the horizontally transverse axis to the x-direction; and the z-direction corresponds to the vertical axis.
Such module carrier assemblies are situated between the A-pillars of a motor vehicle and carry instruments and other components arranged in the area of the dashboard of a vehicle, for example one or a plurality of airbags or the like. The center console is often also connected to such an assembly. Furthermore, the steering column or a steering column module including the steering column is connected to such an assembly. In addition to the steering column, such a steering column module may include steering-assist actuators or other components.
Module carrier assemblies of this type include a transverse carrier which extends between the two A-pillars of the vehicle and is connected to these A-pillars. In a plurality of cases, such transverse carriers, also referred to as cross car beams, are implemented as hollow chamber profiles. To be able to configure the desired geometries, such transverse carriers implemented as hollow chamber profiles are often implemented as a semi monocoque construction or as a closed profile, for example as a tube or extrusion profile. In such a case, the transverse carrier is composed of two half shells, the joining plane of the two half shells being approximately located in the y-z plane (the vertical transverse plane) and also approximately in the x-y plane (the horizontal transverse plane) of the vehicle. Such a transverse carrier includes a front half shell and a rear half shell, which as a general rule are intermaterially connected to each other, for example by joining.
The steering column connected to the transverse carrier of such a module carrier assembly is in operative connection with the steered wheels and extends, at least in the case of vehicles having a front engine, into the engine compartment. Vibrations are coupled into the steering column, which are caused by the steered wheels and/or by the operation of the engine when driving. These vibrations are transmitted to the steering wheel. By connecting the steering column or the steering column module to the module carrier assembly, vibrations are also coupled into their transverse carriers. On account of the size of the steering column or the entire steering column unit, which is connected to the module carrier assembly, its natural frequency is relatively low. When configuring steering columns or steering column modules, one strives to devise these steering columns or steering column modules preferably in such a manner that the natural frequency does not correspond to the natural frequency of the engine and differs from the natural frequency of the engine by a certain frequency spacing, in particular to avoid or at least reduce vibrations and/or structure-borne noise. As a general rule, a natural frequency of the engine of approximately 30 Hz is assumed. On this basis, it is often required that the steering column for use in a passenger car in the installed state has a natural frequency of at least 40 Hz. Using these measures, one would like to achieve that, in order to avoid disruptive noises, the steering column is excited by its natural frequency. This would perhaps not negatively affect the functional efficiency; however, it is perceived as disruptive.
Such a steering column or steering column module is connected to the transverse carrier of the module carrier assembly by means of at least one steering column holder. Such a steering column holder is, in principle, an angle piece which is supported on the outer side of the transverse carrier on the side of the steering wheel and engages having its other limb below the transverse carrier. Such a steering column holder is welded to the transverse carrier. As a general rule, the steering column itself is, by means of screws, connected on the side of the transverse carrier to the steering column holder(s). On account of the connection of the steering column to the transverse carrier of the module carrier assembly, this assembly also influences the vibration behavior of the steering column. Such a connection of the steering column or the steering column module to the transverse carrier may increase the natural frequency of the steering column by approximately 0.2 Hz.
To prevent undesirable vibrations in the vehicle and, in particular, in the vehicle interior, active damping systems have been developed, the actuators of which generate counter-vibrations, to eliminate vibrations which are possibly unpleasantly perceived. Such active damping systems for damping the vibrations at, for example, a module carrier assembly are known from DE 10 2004 013 343 A1 or DE 10 2005 030 934 A1. Even though such damping systems compensate for or counteract undesirable vibrations, these damping systems are complex and in many cases are not desired. These damping systems are located at the interface of the transverse carrier of the module carrier assembly and the respective A-pillar.
DE 10 2009 026 299 A1 discloses a cockpit carrier for a motor vehicle. The transverse carrier of this prior art is a box-shaped hollow body profile. Two steering column holders are connected thereto. Each steering column holder is configured as a flat part, manufactured from a sheet metal plate. According to the concept of the prior art, it is provided that the flat parts have cross-sectional wall elements—also referred to as partition elements—within the transverse carrier. In so doing, the transverse carrier is to be stiffened. These flat parts engage with their partition wall from below—and, thus, in the z-direction—into the transverse carrier. These flat parts extend over the entire cross-sectional area of the transverse carrier and are connected to the entire circumference of the inner contour of the transverse carrier. The partition elements protrude at the bottom from the transverse carrier. The actual part of each flat part, which is used for the steering column connection, extends only at a distance from the underside of the transverse carrier in the x-direction.
WO 2008/009683 A1 discloses an arrangement for attaching a steering column of a motor vehicle. The subject of this document is that the steering column holder is connected to the transverse carrier by two flanges forming a U-shaped accommodation. These flanges enclose the transverse carrier on the outer side, namely on the outer sides of the box-shaped transverse carrier facing the x-direction. The steering column itself is connected by holding means integrally formed on the U-shaped transverse-link accommodation. This document discloses that a threaded sleeve is provided, which extends from the outer side into the transverse carrier up to the inner side.
DE 10 2008 026 631 A1 discloses a dashboard support for a motor vehicle. The subject of this document is such a dashboard support having slots into which the limbs of steering column holders are insertable and therein adjustable to establish an intended positioning. For this dashboard support, it is not provided that the steering column holders are supported on an outer wall of the transverse carrier and configured as an angle piece, so as to in this manner enclose two sides of the transverse carrier.
The foregoing examples of the related art and limitations therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.